Recently, photoresist copolymers wherein alicyclic monomers have been introduced into the main chain or branched chain have proven to be useful to obtain ultra-micro patterns. However, photoresist copolymers consisting of alicyclic monomers typically have a low polymerization yield, thereby synthesis of the copolymer requires high production cost.
In addition, as the amount of the monomer employed in the polymerization increases, the polymerization yield is noticeably lowered, so that the photoresist polymer can be hardly prepared on a large scale.